Thread: High boost plugs

^^^I already talked to one of their (NGKs) reps and they said that extreme changes in hot/cold will cause ceramic to break in extreme cases. Which this case was pretty extreme. I went from 7000rpm into fuel cut decel and fresh cold 20* air. They said it was rare, but happens. That's why they suggested these. I have always heard that a projected plug is good for response, but they are more prone to issues from ceramic cracking than plugs that don't project into the cylinder as far.

I am one of 4 people local who have broken plugs this past winter. All of them were on boost levels lower than mine, yet still had issues.

All I know is if I spend 2000 on a motor build I don't wanna have a cheap plug damage it. This motor lasted through 14K miles of hell, with hundreds of drag passes is 100*+ heat without any issues up to 20psi of boost. Yet one cruise on low boost in frigid temps causes this. I am going to do everything I can to prevent it.

Motor still runs amazing, there is prob some small pitting on the piston though. The motor just needs to last till the end of this season anyway, so I can tear it down and replace the leaking cometic gasket. It leaks from the timing cover above where the silicon adhesive goes. I thought it was just a bad silicon bead on the gasket, but it is leaking above that. First time I have ever seen that. I guess I could machine the oil pump cover down as well to get better fitment.